GENERAL TECHNICAL CHARACTERISTICS OF FIXED TELECOMMUNICATIONS

HKTA 2201

ISSUE 5 AUGUST 2005

GENERAL TECHNICAL CHARACTERISTICS

OF FIXED TELECOMMUNICATIONS NETWORKS

IN HONG KONG

TELECOMMUNICATIONS AUTHORITY

HONG KONG

HKTA 2201 ISSUE 5 PAGE i AUGUST 2005

FOREWORD

1. In order to facilitate network interconnection and service interoperability between

wireline equipment and the fixed telecommunications networks, there is a need to

specify the relevant technical characteristics on the network side. This specification

defines the general technical characteristics of the fixed telecommunications networks

in Hong Kong. The Fixed Telecommunication Network Services (FTNS) operators

shall comply with this specification as well as other applicable codes of practice and

guides issued by the Telecommunications Authority (TA).

2. As different switching systems and technologies are employed by the FTNS operators,

the characteristics of each network may differ. Details of the individual network

characteristics and services offered are available direct from the FTNS operators.

Contact information of the FTNS operators can be found in the information note

OFTA I 412 titled "How to apply for certification of customer premises equipment to

be connected to the public telecommunications network in Hong Kong" issued by the

Telecommunications Authority (TA).

3. The Telecommunications Authority (TA) reserves the right to revise the contents of

this specification without prior notice. Amendments or re-issues of this specification

may not be distributed automatically to the FTNS operators and equipment

manufacturers / suppliers and it will be their responsibility to ensure that their

equipment conform to the latest requirements.

4. The TA accepts no responsibility for the satisfactory end-to-end performance of

wireline equipment connected to the networks of the FTNS operators. This

specification does not address performance, reliability or quality-of-service

parameters.

5. The HKTA series specifications and information notes issued by the TA can be

obtained through one of the following methods:-

• downloading direct through the Office of Telecommunications Authority's

(OFTA)’s Internet Home Page. The Home Page address is

http://www.ofta.gov.hk;

• making a request for hard copies to :-

Senior Telecommunications Engineer

Standards Section

Office of the Telecommunications Authority

29/F Wu Chung House

213 Queen’s Road East

Wanchai

Hong Kong

Fax : +852 2838 5004

Email : [email protected]

HKTA 2201 ISSUE 5 PAGE ii AUGUST 2005

6. Enquiries about this specification may be directed to :

Senior Telecommunications Engineer

Standards Section

Office of the Telecommunications Authority

29/F Wu Chung House

213 Queen’s Road East

Wanchai

Hong Kong

Fax: +852 2838 5004 Email : [email protected]

HKTA 2201 ISSUE 5 PAGE iii AUGUST 2005

AMENDMENT HISTORY

Item Issue No. Paragraph Descriptions

1. Issue 2 Foreword Update information for FTNS operators and for OFTA

2. Issue 2 Clause 1 Include editorial changes

3. Issue 2 Clause 2 Rewrite as clause 2.1 to 2.2

4. Issue 2 Clause 3 Change title to “Numbering”.

Rewrite clause 3.1 and delete clauses 3.2 and 3.3

5. Issue 2 Clause 4 Change title to “Basic Characteristics of Direct Exchange Line”

Move original requirements on basic ringing signal to clause 4.2.

Add new clauses 4.1, 4.3 and 4.4

6. Issue 2 Clause 5 Change title to “Basic Tone Characteristics”

Include editorial changes and restructure clauses 5.1 to 5.4. Make

clarification on power levels of basic tones

7. Issue 2 Clause 6 Include editorial changes Restructure clause 6.3.1 as clauses 6.3.1 to 6.3.3

8. Issue 2 Clause 7 Delete original clause 7.1

Move old clause 7.2 to 7.1. Add new clauses 7.2 and 7.3

9. Issue 2 Clause 8 Update reference documents

10. Issue 2 Annex 1 Include editorial changes and add information on supplementary

ringing signals

11. Issue 2 Annex 2 Include editorial changes

12. Issue 2 Annex 3 Add new Annex 3 on nominal pad settings of FTNS operators

13. Issue 3 Clause 4 Revise clause 4.1.6 regarding the timing value

14. Issue 3 Clause 5 Delete clause 5.4 regarding requirement on other tones

15. Issue 3 Clause 7 Update the references to ITU-T recommendations in clauses 7.1 and

7.2

16. Issue 3 Clause 8 Update the categories of ITU-T recommendations in clause 8.3

17. Issue 3 Annex 2 Include editorial changes

18. Issue 4 Clauses 8 and 9 Add new clause 8 on POTS splitter characteristics; previous clause 8

moved to clause 9

19. Issue 4 Annex 1 Update company names of FTNS operators


HKTA 2201 ISSUE 5 PAGE iv AUGUST 2005

Item Issue No. Paragraph Descriptions


22. Issue 4 Annex 4 Add new Annex 4 : Characteristics of POTS Splitter for Broadband

Type-II Interconnection at the Exchange Side of the Fixed

Telecommunications Networks in Hong Kong

23. Issue 5 Foreword Editorial amendments.

24. Issue 5 Clause 4.2.5 Update the requirement on ringing time-out.

25. Issue 5 Clause 5.2.2 Update the requirement on ringing tone.

HKTA 2201 ISSUE 5 PAGE v AUGUST 2005

CONTENTS

1. SCOPE

2. NETWORK CONNECTION SPECIFICATION

3. NUMBERING

4. BASIC CHARACTERISTICS OF DIRECT EXCHANGE LINE

5. BASIC TONE CHARACTERISTICS

6. BASIC ANALOGUE TRANSMISSION CHARACTERISTICS

7. BASIC DIGITAL TRANSMISSION CHARACTERISTICS

8. SPLITTER CHARACTERISTICS FOR PARTIAL BANDWIDTH OPTION

9. REFERENCE

Annex 1 Summary of the Ringing Signals of the Fixed Telecommunications

Networks in Hong Kong

Annex 2 Summary of the Basic Tones of the Fixed Telecommunications Networks in

Hong Kong

Annex 3 Nominal Pad Settings of the Fixed Telecommunications Networks in Hong Kong

Annex 4 Characteristics of POTS Splitter for Broadband Type-II Interconnection at the

Exchange Side of the Fixed Telecommunications Networks in Hong Kong

HKTA 2201 ISSUE 5 PAGE 1 AUGUST 2005

1. SCOPE

This technical specification defines the general technical characteristics of the fixed

telecommunications networks in Hong Kong.

2. NETWORK CONNECTION SPECIFICATION

2.1 USER-TO-NETWORK CONNECTION

The fixed telecommunications network (the network) shall be able to work with

customer premises equipment (CPE) which comply with the relevant HKTA 20XX

series specifications issued by the Telecommunications Authority (TA).

2.2 NETWORK-TO-NETWORK CONNECTION

The network shall comply with the relevant HKTA 22XX series specifications issued

by the TA for network-to-network connection.

3. NUMBERING

3.1 The network shall have numbering structure and digit handling capability to support :

(a) The Numbering Plan for Telecommunications Services in Hong Kong issued

by the TA; and

(b) ITU-T Recommendation E.164 on “The International Public

Telecommunication Numbering Plan”.

4. BASIC CHARACTERISTICS OF DIRECT EXCHANGE LINE

4.1 BASIC LINE AND DIALLING SIGNALS

4.1.1 Idle State Condition

The idle state condition of the direct exchange line (DEL) is equivalent to the on-hook

state. The idle state condition of the DEL on the network side shall be earth on Tip

(A-wire) and a nominal voltage of -40 to -48 Vdc on Ring (B-wire).


4.1.2 Seizure Signal

The network shall support loop-start method used by the CPE as a seizure signal for

DEL.

4.1.3 Dialling Signal

The network shall support both tone dialling (DTMF signalling) and pulse dialling

(loop-disconnect signalling) signals sent by the CPE.

4.1.4 Answer Signal

Answer signal to the CPE of the calling party is an optional network facility.

If answer signal is provided by the network to the CPE of the calling party, the answer

signal shall be a reversal of line polarity when the CPE of the called party answers the

call, i.e. negative voltage on Tip and earth on Ring. The magnitude of the negative

voltage on Tip will depend on the d.c. loop condition in off-hook state.

4.1.5 Clear Signal

The network shall recognise the disconnection of seizure loop (i.e. restoration to idle

state) by the CPE for a duration of 1 second or more as a clear signal for release of a

call connection.

4.1.6 Re-answer Supervision

When clear signal is sent by the CPE of the called party and re-answer supervision is

supported by the network, the network shall release the call connection when the

restoration to idle state has been maintained by the CPE of the called party until the

expiry of network re-answer supervision timing. The re-answer supervision timing

shall have a maximum value of 40 seconds.

Note: The long-term objective of re-answer supervision timing is 20 seconds maximum.

4.2 BASIC RINGING SIGNAL

4.2.1 General

The basic ringing signal is the signal sent from the network to the CPE of the called

party for call set-up purpose. The network shall provide basic ringing signal with

characteristics as defined in clauses 4.2.2 to 4.2.5.


4.2.2 Ringing Frequency and Voltage

Frequency : Range from 20 Hz to 28 Hz

Voltage : Ringing voltage of 75 + 20 Vrms shall be superimposed on -40 to -48

Vdc (at exchange side with line impedance of 0 to 1000 Ω).

4.2.3 Ringing Cadence

The cadence for the basic ringing signal shall be as follows with tolerance of + 10%:-

0.4 second ON

0.2 second OFF

0.4 second ON

3.0 second OFF

4.2.4 Immediate Ringing Cadence

If immediate ringing is provided by the network, the first ON period of the first cycle

of the ringing cadence described in clause 4.2.3 shall be in the range of 0.4 to 0.9

second.

4.2.5 Ringing Time-Out

If ringing time-out is provided by the network, ringing shall automatically be ceased

by the network after about 1 to 2 minutes. Upon ringing time-out, the called DEL

shall be restored to idle state condition and busy tone shall be returned to the calling

party in place of ringing tone as specified in clause 5.2.2.

4.2.6 A summary on the existing characteristics of the basic ringing signals of the fixed

telecommunications networks in Hong Kong is tabulated in Annex 1.

4.3 SUPPLEMENTARY RINGING SIGNALS

4.3.1 Supplementary ringing signals other than the basic ringing signal defined in clause

4.2 for the operation of enhanced customer services is optional network facility.

If supplementary ringing signals are provided by the network, the ringing signals shall

have technical characteristics same as the basic ringing signal except for the ringing

cadence defined in clause 4.2.3.

4.3.2 A summary on supplementary ringing signals provided by the fixed

telecommunications networks in Hong Kong is given in Annex 1.


4.4 HOOK FLASH SIGNAL

4.4.1 Hook flash signal is an optional network facility to support operation of enhanced

customer services.

If hook flash signal is supported by the network, the network shall recognise the

momentary disconnection of seizure loop by the CPE for a duration of 300 to 700 ms

as a hook flash signal and differentiate it from the clear signal defined in clause 4.1.5.

5. BASIC TONE CHARACTERISTICS

5.1 GENERAL

The network shall provide the basic tones as defined in clause 5.2. The basic tones

shall have the technical characteristics defined in clause 5.3.

5.2 DEFINITION OF TONES

5.2.1 Dial Tone

When the calling party initiates a call to the network, dial tone shall be returned as

soon as the network is in a state ready to receive the incoming dialling signals. The

tone shall be removed as soon as the network detects the first dialled digit.

5.2.2 Ringing Tone

When the called party is ready to receive a call, a basic ringing tone, complying with

the technical characteristics in clause 5.3, or other forms (such as music, songs etc.)

can be returned to the calling party.

5.2.3 Busy Tone (Customer Busy)

Busy tone shall be returned to the calling party when the called party is engaged or in

a "locked-out" condition.

5.2.4 Congestion Tone (Network Busy)

Congestion tone shall be returned to the calling party when the network is busy.

5.2.5 Number Unobtainable (NU) Tone

Number unobtainable tone shall be returned to the calling party to indicate that the

called number is :

• out of service,

• a spare code or number,

• the access code of a service which is not available to the calling party, or not

accessible due to certain service restrictions.


5.3 TECHNICAL CHARACTERISTICS

5.3.1 Frequencies And Cadences

(a) The frequency and cadence of the basic tones are defined in the following table.

Item Type of Tone Frequency (Hz) Cadence (Second)

i. Dial Tone 350 + 440 Continuous

ii. Ringing Tone 440 + 480 0.4 sec ON / 0.2 sec OFF /

0.4 sec ON / 3.0 sec OFF

iii. Busy Tone 480 + 620 0.5 sec ON / 0.5 sec OFF

iv. Congestion Tone 480 + 620 0.25 sec ON / 0.25 sec OFF

v. Number

Unobtainable Tone 480 + 620 Continuous

(b) The frequency tolerance for the above tones is ±1.0%.

(c) The cadence tolerance for the above tones is ±10%.

5.3.2 Power Levels

(a) In accordance with ITU-T Recommendation E.180 (equivalent with Q.35), the power

levels of the ringing tone, busy tone, congestion tone, and number unobtainable tone

are defined at a zero relative level point at the incoming (in the traffic direction) end

of the network-to-network interface (see Figure 1). For the combined tone signals

resulting from combination of frequency components, the power levels so defined

shall have a nominal value of -10 dBm0 measured with continuous tone (or -16 dBm0

at the main distribution frame (MDF) of the local exchange of the network) and the

values shall be in the range -5 to -15 dBm0 (or -11 to -21 dBm0 at the MDF).

(b) For the power level of the dial tone, the point of reference is the MDF of the local

exchange of the network, where the DEL is connected. The absolute power of the

combined tone signal at the 2-wire access in the direction towards the CPE is

normally in the range of –10 dBm ± 5 dB. To avoid interference with multi-frequency

push button receivers at the local exchange, dial tone level higher than -10 dBm

should be avoided.

(c) Each harmonic shall not exceed -50 dBm or shall be at least 30 dB below the signal

level for individual frequency component.


5.3.3 A summary on the existing characteristics of the basic tones provided by the fixed

telecommunications networks in Hong Kong is tabulated in Annex 2.

6. BASIC ANALOGUE TRANSMISSION CHARACTERISTICS

6.1 PASS-BAND

All the exchange lines and trunks of the network shall have a nominal pass-band of

300 to 3400 Hz, with 600 Ω nominal non-reactive terminating impedance for

telephony services. Echo cancellers / suppressers will not be provided by the

operators.

6.2 LOCAL LOOP ATTENUATION

The local loop for the exchange lines and trunks of the network shall have attenuation

less than 10 dB at 1600 Hz depending on the length of the loop.

6.3 JUNCTION (INTER-EXCHANGE CIRCUITS) LOSS

6.3.1 Pad Settings For Transmission Paths

Figure 1 shows the pad settings T and R for the "send" path and the "receive" path

respectively between the network side and the CPE side. As a general principle, it is

required that the ITU-T Recommendations concerning loudness ratings (G.121) and

stability & echo (G.122) be followed.

6.3.2 The individual values for T and R in conjunction with the nominal CPE loudness rating

performance shall meet the long term objectives for loudness rating requirements

referred to the Virtual International Connecting Points (VICP) as specified in G.121,

i.e. Send Loudness Rating (SLR) = 7 to 9 dB;

Receive Loudness Rating (RLR) = 1 to 3 dB

6.3.3 The nominal value of the differential loss (R-T) is 6 dB at 1600 Hz; in all cases (R-T)

shall be in the range of 3 to 9 dB.

Note: The nominal values of the T and R pads set by the fixed telecommunications

networks in Hong Kong are given in Annex 3.


Figure 1 Pad Setting for Transmission Paths

Analogue Transmission Analogue-Digital Coder

Digital Transmission Digital-Analogue Decoder

Analogue Pads Digital Switching

T R

0 dBr0 dBr0 dBr

Network 1 Network 2Interface

"Send" "Receive"

MDF

T R

0 dBr

"Send""Receive"

CPE

0 dBr 0 dBr

TR

MDF

Legend :

CPE


6.3.4 The junction circuits (inter-exchange circuits) of the network are fully digital with no

attenuation loss. Taking into account the local loop attenuation and the pad setting,

a telephone call within Hong Kong may have an overall nominal attenuation of 26 dB

(10 dB local + 6 dB pad setting + 10 dB local).

6.3.5 International circuits of the network are fully digital. The nominal attenuation

between the CPE and the international gateway is 10 dB (10 dB local + 0 dB pad

setting) for the "send" path and 16 dB (10 dB local + 6 dB pad setting) for the

"receive" path respectively.

6.4 TRANSIENT VOLTAGES AND INTERFERENCE COMPONENTS

The network under normal circumstances may have transient voltages imposed upon it

which may reach a peak of several hundred volts. Interference power components

that may exist on exchange lines and trunks shall be subject to the following limits :

- Longitudinal induced voltages up to 20 Vrms at 50 Hz.

- Uniform spectrum and random noise having a power up to -45 dBm over the band

300 to 3400 Hz.

- Random impulse noise up to -22 dBm.

7. BASIC DIGITAL TRANSMISSION CHARACTERISTICS

7.1 DIGITAL TRANSMISSION CHARACTERISTICS AT 1544 kbit/s (T1)

Where digital interfaces are employed by the network at 1544 kbit/s, the following

characteristics shall be followed:

(a) The physical/electrical characteristics of the 1544 kbit/s digital interface shall

be in accordance with the relevant section of ITU-T Recommendation G.703.

(b) The basic frame structure and characteristics of the 1544 kbit/s digital interface

shall be in accordance with the relevant sections of ITU-T Recommendation

G.704.

(c) The control of jitter and wander for the 1544 kbit/s digital interface shall

comply with ITU-T Recommendation G.824.


7.2 DIGITAL TRANSMISSION CHARACTERISTICS AT 2048 kbit/s (E1)

Where digital interfaces are employed by the network at 2048 kbit/s, the following

characteristics shall be followed:

(a) The physical/electrical characteristics of the 2048 kbit/s digital interface shall

be in accordance with the relevant section of ITU-T Recommendation G.703.

(b) The basic frame structure and characteristics of the 2048 kbit/s digital interface

shall be in accordance with the relevant sections of ITU-T Recommendation

G.704.

(c) The control of jitter and wander for the 2048 kbit/s digital interface shall

comply with ITU-T Recommendation G.823.

7.3 DIGITAL TRANSMISSION CHARACTERISTICS AT OTHER HIERARCHY BIT

RATES

Where digital interfaces are employed by the network using digital hierarchy bit rates

other than 1544 kbit/s and 2048 kbit/s, the technical characteristics shall follow

internationally accepted standards.

8. SPLITTER CHARACTERISTICS FOR PARTIAL BANDWIDTH OPTION

8.1 POTS SPLITTER

Where line-sharing with telephony services using a pass-band specified in Clause 6.1

is required to implement the partial bandwidth option of Broadband Type II

Interconnection, a splitter shall be provided at the exchange side. The technical

characteristics of the splitter shall follow the specification tabulated in Annex 4.

9. REFERENCE

9.1 Network Connection Specifications issued by the TA

HKTA 20XX Series Network Connection Specifications for Connection

of Customer Premises Equipment (CPE) to the


Public Telecommunications Networks (PTNs) in

Hong Kong

HKTA 22XX Series Network Connection Specifications for

Network-to-Network Connection of the Public

Telecommunications Networks (PTNs) in Hong

Kong

9.2 The Numbering Plan for Telecommunications Services in Hong Kong issued by the

Telecommunications Authority

9.3 Relevant Recommendations issued by the ITU-T

E-Series Recommendations Overall Network Operation, Telephone Service,

Service Operation and Human Factors

G-Series Recommendations Transmission Systems and Media, Digital

Systems and Networks

P-Series Recommendations Telephone Transmission Quality, Telephone

Installations, Local Line Networks

Q-Series Recommendations Switching and Signalling

- END -

HKTA 2201 ISSUE 5 PAGE 1 OF ANNEX 1 AUGUST 2005

Annex 1 Summary of the Ringing Signals of the Fixed Telecommunications Networks in Hong Kong

Item Description Reference Value

Adopted by the

TA

PCCW-HKT Telephone

Ltd.

Wharf T&T Ltd.

(WT&T)

Hutchison

Global

Communications

Ltd. (HGC)

New World

Telecommunications Ltd.

(NWT)

Remarks

1. Basic Ringing

Signal

a. Frequency

(min, max.)

Hz

(20 , 28 )

(23.5, 27.5) 20

with tolerance

+/- (1/3) Hz

(22, 28) (22, 28) 20

with tolerance

+/- (1/3) Hz

All Complied

b. Cadence 0.4 sec ON,

0.2 sec OFF,

0.4 sec ON,

3.0 sec OFF

with tolerance of

+/- 10%

0.4 sec ON,

0.2 sec OFF,

0.4 sec ON,

3.0 or 3.2 sec OFF

0.4 sec ON,

0.2 sec OFF,

0.4 sec ON,

3.2 sec OFF

0.4 sec ON,

0.2 sec OFF,

0.4 sec ON,

3.0 sec OFF

0.4 sec ON,

0.2 sec

OFF,

0.4 sec ON,

3.0 sec

OFF

0.4 sec ON,

0.2 sec OFF,

0.4 sec ON,

3.0 sec OFF

All Complied

c. Voltage 75 +/- 20 Vrms

superimposed

on -40 to -48V

dc (at exchange

MDF)

75 +/- 20 Vrms

superimposed on -40 to -48V

dc (at exchange MDF)

86 Vrms 75 +/- 20Vrms

75Vrms 86 Vrms All Complied

d. Immediate

Ringing If applicable, the

range should be

0.4 to 0.9 sec.

The first ON period of the

first cycle of ringing cadence

may vary from 0.4 to 0.8 sec.

Not Applicable 0.4 to 0.9 sec Not

Applicable

Not

Applicable

All Complied

e. Ringing

Time-out If applicable, the

range should be

60 to 120 sec.

About 120 sec. Upon

time-out, the called DEL will

restore to idle status and

busy tone will be returned to

the calling party in place of

ringing tone.

120 seconds 60 to 120 sec Not

Applicable

120 seconds All Complied



Adopted by the

TA

PCCW-HKT Telephone

Ltd.

Wharf T&T Ltd.

(WT&T)

Hutchison

Global

Communications

Ltd. (HGC)

New World


(NWT)

Remarks

2. Supplementary

Ringing

Signals

a. Frequency,

Voltage,

Immediate

Ringing, and

Ringing

Time-out

Same as 1a and

1c to 1e Same as 1a and 1c to 1e Same as 1a and 1c

to 1e

Same as 1a and 1c

to 1e Same as 1a

and 1c to 1e Same as 1a

and 1c to 1e All Complied

b. Cadence Nil Requirement DN 'B' of Duplex Ringing

Feature:

1.2 sec ON, 3.0 sec OFF

Option 1:

1.2 sec ON, 3.0 sec

OFF

Option 2:

0.4 sec ON, 0.2 sec

OFF, 0.4 sec ON,

0.2 sec OFF, 0.8

sec ON, 0.4 sec

OFF

Option 3:

0.5 sec ON, 0.5 sec

OFF, 1.0 sec ON,

0.5 sec OFF, 0.5

sec ON, 3.0 sec

OFF

DN 'B' of Duplex

Ringing Feature : 1.2 sec ON, 3.0

sec OFF

Not

specified Not

specified


Annex 2 Summary of the Basic Tones of the Fixed Telecommunications Networks in Hong Kong


Adopted by the

TA

PCCW-HKT

Telephone Ltd.

Wharf T&T Ltd.

(WT&T)

Hutchison

Global

Communications

Ltd. (HGC)

New World


(NWT)

Remarks

1. Dial Tone

i. Frequency (Hz)

ii. Cadence

350 + 440

Continuous

350 + 440

Continuous

350 + 440

Continuous

350 + 440

Continuous

350 + 440

Continuous

350 + 440

Continuous

All Complied

2. Ringing Tone

i. Frequency (Hz)

ii. Cadence

440 + 480

0.4 sec ON,

0.2 sec OFF,

0.4 sec ON,

3.0 sec OFF

440 + 480

0.4 sec ON,

0.2 sec OFF,

0.4 sec ON ,

3.0 or 3.2 sec OFF

(the first ON

period of the first

cycle of ringing

tone may vary

from 0.4 to 0.8 sec

due to the

application of

immediate ringing

tone)

440 + 480

2.0 sec ON,

4.0 sec OFF

440 + 480

0.4 sec ON,

0.2 sec OFF,

0.4 sec ON,

3.0 sec OFF

440 + 480

0.4 sec ON,

0.2 sec OFF,

0.4 sec ON,

3.0 sec OFF

440 + 480

2.0 sec ON,

4.0 sec OFF

New equipment

purchased and

installed by WT&T

and NWT after 1

January 1999 shall

comply with the

reference value

3. Busy Tone

i. Frequency (Hz)

ii. Cadence

480 + 620

0.5 sec ON,

0.5 sec OFF

480 + 620

0.5 sec ON,

0.5 sec OFF

480 + 620

0.5 sec ON,

0.5 sec OFF

480 + 620

0.5 sec ON,

0.5 sec OFF

480 + 620

0.5 sec ON,

0.5 sec OFF

480 + 620

0.5 sec ON,

0.5 sec OFF

All Complied




Adopted by the

TA

PCCW-HKT

Telephone Ltd.

Wharf T&T

Ltd.

(WT&T)

Hutchison

Global

Communications

Ltd. (HGC)

New World


(NWT)

Remarks

4. Congestion Tone

i. Frequency (Hz)

ii. Cadence

480 + 620

0.25 sec ON,

0.25 sec OFF

480 + 620

0.25 sec ON,

0.25 sec OFF

480 + 620

0.25 sec ON,

0.25 sec OFF

480 + 620

0.25 sec ON,

0.25 sec OFF

480 + 620

0.25 sec ON,

0.25 sec OFF

480 + 620

0.25 sec ON,

0.25 sec OFF

All Complied

5. Number

Unobtainable Tone

i. Frequency (Hz)

ii. Cadence

480 + 620

Continuous

480 + 620

Continuous

480 + 620

Continuous

480 + 620

Continuous

480 + 620

Continuous

480 + 620

Continuous

All Complied

6.1 Power Level of

Ringing Tone,

Busy Tone,

Congestion Tone

and Number

Unobtainable Tone

Combined tone

power level shall

have nominal

value of -10

dBm0 measured

with continuous

tone (or -16

dBm0 at the

MDF) and the

values shall be in

the range

-5 to – 15 dBm0

(or -11 to

-21dBm0 at the

MDF)

At the local

exchange MDF

power level of

each single

frequency tone

component is

-19 +/- 1 dBm,

giving a combined

tone power level

of

-16 +/- 1 dBm

Combined tone

power level

Ringing Tone :

-16 dBm

Busy Tone :

-21 dBm

Congestion tone :

-21 dbm

Number

unobtainable tone :

-10 dBm

Combined tone

power level is in

range -13 dBm to

-21 dBm

measured at the

MDF

Combined

tone power

level is -13 +/-

1 dBm

Combined tone

power level

Ringing Tone :

-16 dBm

Busy Tone :

-21 dBm

Congestion

tone :

-21 dbm

Number

unobtainable

tone :

-21 dBm

New equipment

purchased and

installed by WT&T

and NWT after 1

January 1999 shall

comply with the

reference value




Adopted by the

TA

PCCW-HKT

Telephone Ltd.

Wharf T&T Ltd.

(WT&T)

Hutchison

Global

Communications

Ltd. (HGC)

New World


(NWT)

Remarks

6.2 Power Level of

Dial Tone

The absolute power

level of combined

tone measured at

the local exchange

MDF shall be in

the range of –10

dBm ± 5 dB and level higher

than –10 dBm

should be avoided

Same as 6.1 Combined tone

power level for dial tone is

-10 dBm

Same as 6.1 Same as 6.1 Combined

tone power

level for dial tone is

-10 dBm

All Complied

7. Frequency

Tolerance

of Tone

+/- 1%

+/- 0.5 % +/- 0.5 % +/- 1% +/- 4Hz +/- 1% All Complied

8. Cadence Tolerance

of Tone

+/- 10% +/- 10% +/- 10% + /- 10% +/ - 10 ms +/- 10% All Complied

9. Harmonic of Tone Either one of the

followings is

accepted : -

a) less than

-50 dBm ; or

b) 30 dB below the

signal level.

Less than -50 dBm At least 30 dB

below signal level

30 dB below the signal

level for individual

frequency components

Less than -55

dBm

At least 30

dB below

signal level

All Complied


Annex 3 Nominal Pad Settings of the Fixed Telecommunications Networks in Hong Kong

The nominal values of the T and R pads (see clause 6.3.3 of this specification) set by the FTNS

operators in Hong Kong are as follows:

FTNS Operator T / R

PCCW-HKT Telephone Limited 0 / 6 dB New World Telecommunications Limited 0 / 6 dB

Hutchison Global Communications Limited 0 / 7 dB

Wharf T&T Limited 2 / 8 dB


Annex 4 Characteristics of POTS Splitter for Broadband Type-II Interconnection at the

Exchange Side of the Fixed Telecommunications Networks in Hong Kong

Parameter Reference Clause in ITU-T

Rec. G.992.1 Annex E

Performance Requirement

(Frequency Limit)

Insertion Loss E.1.3 1004 Hz < 1 dB

Insertion Loss Distortion E.1.4 250 – 4000 Hz < +/- 1 dB

Return Loss E.1.2 300 Hz > 14 dB

1000 Hz > 18 dB

2000 Hz > 18 dB

3400 Hz > 14 dB

Delay Distortion E.2.3.1.4 200 – 600 Hz < 250 µs

600 – 3200 Hz < 200 µs

3200 – 4000 Hz < 250 µs

Longitudinal Balance E.2.3.2.1 200 – 1000 Hz > 58 dB

3000 Hz > 53 dB

ADSL Band Attenuation E.2.4.1 32 – 300 kHz > 65 dB

300 – 1104 kHz > 55 dB

Loading of ADSL Signal Path E.2.4.2 30 – 1104 kHz < 0.25 dB

Capacitance in Idle State E.2.3.3.1 20 – 30 Hz < 0.3 µF

DC Resistance with U-interface

Open

E.2.2 > 5 M ohms

DC Resistance with U-interface

Shorted

E.2.2 < 25 ohms

NOTE:

1. For measurement of loss or loss distortion, a matching impedance of 600 ohms shall be used

for termination.

2. The method of measurement shall follow that specified in the corresponding reference

clause in the ITU-T recommendation.

3. For Capacitance in idle state, some legacy equipment may have a value of up to 0.5 µF.

Date post:	03-Feb-2022
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GENERAL TECHNICAL CHARACTERISTICS OF FIXED TELECOMMUNICATIONS

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